1. Field of the Invention
The present invention relates to a washing machine, and more particularly, to a drum type washing machine combined with a dryer, in which a lint filter assembly is provided to collect and remove foreign substances such as lint generated during a heat drying operation.
2. Description of the Related Art
A washing machine is a home appliance for washing clothes automatically. A typical washing machine uses an electric motor as a driving unit to agitate clothes together with water containing detergent to remove dirt from the clothes. The washing process of the washing machine generally includes washing, rinsing, spin-drying, and/or heat-drying operations.
Washing machines can be classified into a drum type washing machine, an agitator type washing machine, and a pulsator type washing machine.
The drum type washing machine includes a plurality of lifters inside of a drum to lift up and drop down clothes in the drum as the drum is rotated about a horizontal axis at a low speed. Therefore, the clothes can be cleaned by the collision with water containing detergent.
Meanwhile, a washing machine combined with a dryer is recently introduced to satisfy user's demand. In this washing machine, clothes are heat dried after washed, rinsed, and spin dried.
The washing machine combined with the dryer can be classified into a condenser type and a vented type depending on a drying method.
The washing machine combined with the condenser type dryer removes residual moisture from clothes by circulating air through a drum, a heat exchanger, and a heater without discharging the air out of the washing machine until the heat drying operation is completed. That is, the air becomes moist after passing through the drum, the moist air cools down at the heat exchanger by exchanging heat with a cooling water, the moisture in the air condenses and drops down to the bottom of the tub as the moist air cools down, and the air is heated again by the heater and then enters the drum again.
In the washing machine combined with the vented type dryer, on the contrary, a heated dry air is blew into a drum to take moisture from clothes and then the air containing lots of moisture is discharged out of the washing machine through a connecting pipe connected between a tub and a vent duct.
However, the moist air, which is discharged from the washing machine combined with the vented type dryer, contains lint such as fluff, thereby contaminating the indoor air.
Further, the lint in the moist air, though it is light, falls down and builds up while it is discharged from the tub to the outside through the vent duct. Particularly, the lint builds up on a pleated surface of the connecting pipe connected between the tub and the vent duct. The build-up of the lint becomes bigger according to the time of use, blocking the vent duct. Further, the build-up of the lint increases the possibility of fire. Therefore, there is an increasing need for a structure that can remove the problems related to the lint.